The present disclosure relates to an image forming apparatus and a development device installed therein.
An electrographic image forming apparatus has performed a developing process by supplying a toner (a developer) from a development device to an electrostatic latent image formed on a surface of a photosensitive drum or the like. The toner used in such a developing process is supplied to the development device from a toner container detachably attached onto the development device. The development device is then provided with a replenishment port for receiving the toner from the toner container. The replenishment port generally may be covered by an openably/closably shutter.
The aforementioned shutter mechanism is illustrated in FIG. 16. A shutter 121 is provided with an inclined plane 122 inclined to diagonally upward and formed with a roughly triangle profile in a side view. The shutter 121 can be linearly slid between one position (refer to a two-dot chain line) to close a replenishment port 124 formed on a development device 123 and another position (refer to a solid line) to open the replenishment port 124. When a toner container (not shown) is not attached onto the development device 123, the shutter 121 is biased to one position to close the replenishment port 124 by a pair of coil springs 125 attached on both sides of the replenishment port 124.
In this situation, when the toner container (not shown) is attached onto the development device 123 from above as indicated by an arrow in FIG. 16, the toner container presses the inclined plane 122 of the shutter 121 from the upper side. Then, the shutter 121 linearly slides from one position to close the replenishment port 124 to another position to open the replenishment port 124.
However, in such a configuration of using the linearly slidable shutter, it is necessary to locate biasing members, such as the coil springs, onto both sides of the replenishment port in order to secure operation stability of the shutter, that is, a plurality of the biasing members are needed. It is therefore feared that the number of components and manufacturing costs increase.